1. Technical Field
The present is directed to elevator dispatching, and more particularly, to optimizing channeling in which floors above the main floor or lobby during up-peak are grouped into sectors, with each sector including a set of contiguous floors and with each sector assigned to a car.
2. Description of the Prior Art
Elevator performance throughout the morning up-peak period is measured, among other criteria, by the speed in which people are moved from the lobby to their respective landings within the building. The time spent by a passenger during a typical up-peak run can be broken into two major phases: waiting time at the lobby and service time to their landing.
During the up-peak period, when two cars leave the lobby partially loaded within a predetermined period of time, the elevator dispatching system typically recalls all elevator cars to the lobby to handle traffic in-coming from the lobby. Hence, a well-known channeling operation is typically activated.
Well-known electronic computer implemented dispatching routines such as channeling enhance elevator system performance during up-peak by reducing the service time for each passenger, while having a minimal effect on the waiting time at the lobby. This enhancement is accomplished by grouping passengers going to the same general area of the building into the same car. Floors above the lobby are divided into sectors. When a car is approaching the lobby, the channeling routine chooses a sector for the car so that the car will only serve floors contained within that sector. The service time (and round trip time) of the car is decreased because of the smaller number of landings being served by the car. See, for example, known channeling routines and implementations disclosed and described in U.S. Pat. No. 4,792,019, Contiguous Floor Channeling With Up Hall Call Elevator Dispatching, Issued Dec. 20, 1988; U.S. Pat. No. 4,804,069, Contiguous Floor Channeling Elevator Dispatching, Issued Feb. 14, 1989; U.S. Pat. No. 4,846,311, Optimized "Up-Peak" Elevator Channeling System With Predicted Traffic Volume Equalized Sector Assignments, and U.S. Pat. No. 5,183,981, "Up-Peak" 0 Elevator Channeling System With Optimized Preferential Service To High Intensity Traffic Floors, which are all hereby incorporated in their entireties by reference.
During one known channeling operation, a group controller or an operational control sub-system divides a building into sectors. The number of sectors is equal to the number of cars in operation (or service) minus one. The size of each sector includes an equal number of floors being served.
The '019 patent teaches a typical channeling routine as shown, for example, in FIGS. 2A-2C herein, which correspond to FIGS. 2A-2C of U.S. '019. Four elevator cars 1-4 which are part of a group elevator system, serve a building having a plurality of floors, e.g. 13, above a lobby; see FIG. 1 herein which corresponds to FIG. 1 of '019. Each car 1-4, contains a car operating panel 12 through which a passenger makes a car call to a floor by pressing a button, producing a signal (CC) identifying the floor to which the passenger intends to travel. On each of the floors, there is a hall fixture 14 through which a hall call signal (HC) is provided to indicate the intended direction of travel by a passenger on the floor. At the lobby (L), there is also a hall call fixture 16 through which a passenger calls the car to the lobby. The depiction in FIG. 1 illustrates cars selected during an up-peak period at which time the floors 2-13, above the main floor, are divided into three sectors, each sector containing four floors. Each of the sectors, which are contiguous, is served by only one of the four cars 1-4 at any time. Such channeling operation is explained in more detail in the flow charts of FIGS. 2A-2C, steps S1-S31, all as shown, described and well-known from U.S. Pat. No. 4,792,019, previously incorporated in its entirety by reference. As shown in FIG. 1, one car, e.g. car 1, is left free. Each car 1-4 will only respond to car calls that are made in the car from the lobby to floors that coincide with the floors in the sector assigned to the car. The car 4, for instance, responds only to car calls made at the lobby to floors 10-13.
The present inventors believe that known channeling routines operate from only one lobby. An adjacent floor to the lobby, such as a subway entrance below the lobby, with heavy up-peak traffic might have long waiting times as the up-peak traffic might not be properly served in, e.g., a dual lobby building having an upper lobby (UL) and a lower lobby (LL). Elevator systems which service a building having a lobby, basement and sub-basement are known; see, e.g., U.S. Pat. No. 4,357,997, Husson et al., Nov. 9, 1982.